The compound [8-chloro-3-(4-chlorobenzyl)-4-difluoro-methoxy-2-ethylquinolin-5-yloxy]acetic acid is described in example 39 of patent citation 1. Patent citation 1 also states that this compound is useful in the treatment and prevention of diseases in which CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells) receptors participate, such as bronchial asthma, chronic obstructive pulmonary disease, allergic airway syndrome, bronchitis, cystic fibrosis, emphysema, rhinitis, etc., and psoriasis, atopic and nonatopic dermatitis, Crohn's disease, ulcerative colitis, and irritable bowel disease, etc.
From that described in patent citation 1 and technical common sense, it can also be understood that this compound is useful in the treatment and prevention of perennial allergic rhinitis, seasonal allergic rhinitis, chronic eosinophilic rhinosinusitis, chronic noneosinophilic rhinosinusitis, chronic spontaneous urticaria, and eosinophilic gastrointestinal disease.
However, patent citation 1 does not mention [8-chloro-3-(4-chlorobenzyl)-4-difluoromethoxy-2-ethylquinolin-5-yloxy]acetic acid or the L-lysine salt thereof in crystal form.